* Convert Liquibase XSD schema to Relax-NG

This is a maven based utility that downloads the [[https://docs.liquibase.com/concepts/changelogs/xml-format.html][liquibase changelog XSD schemas]] from the [[https://mvnrepository.com/artifact/org.liquibase/liquibase-core][liquibase-core jar]], and then uses exec-maven-plugin on the [[https://xmlark.github.io/msv/][Multi-Schema Validator Toolkit]] (formerly known as "Oracle Multi Schema Validator") to convert the liquibase XSD schema to Relax NG (XML notation), and then uses [[https://relaxng.org/jclark/trang.html][trang]] to convert the schema in Relax NG XML notation to Relax-NG compact notation (that can be used by e.g. [[https://www.gnu.org/software/emacs/manual/html_mono/nxml-mode.html][nxml mode in emacs]]).

The XSD schema is extracted from the LATEST version of the liquibase-core jar file.

Usage (example for version 4.32 of the liquibase XSD schema):
 1. Clone this project
    #+begin_example
      mkdir -p ~/git
      cd ~/git/
      git clone https://github.com/steinarb/convert-liquibase-xsd-to-rnc.git
    #+end_example
 2. Build with
    #+begin_example
      cd convert-liquibase-xsd-to-rnc/
      mvn -Dliquibase-xsd.version=4.32 install
    #+end_example
 3. The resulting schemas can be found in the target directory of the project:
    #+begin_example
      drwxr-xr-x 4 sb sb   4096 May 29 17:35 .
      drwxr-xr-x 4 sb sb   4096 May 29 17:35 ..
      -rw-r--r-- 1 sb sb  39593 May 29 17:35 dbchangelog-4.32.rnc
      -rw-r--r-- 1 sb sb 153739 May 29 17:35 dbchangelog-4.32.rng
      drwxr-xr-x 3 sb sb   4096 May 29 17:35 dependency
      drwxr-xr-x 2 sb sb   4096 May 29 17:35 dependency-maven-plugin-markers
    #+end_example
